This is part two about buttonholes in hand knitting.* The first post covered lore and tradition about buttonholes, plus some nifty tricks. Today, background info about the buttons themselves, plus how to sew them on.
Buttons, shanked and unshanked
A buttonhole has to be big enough to let the button through without straining, yet not big the button pops loose when you breathe. Less evident, perhaps, is the interplay between the thickness of the band and the height of the button shank.
Buttons come in two kinds: shanked and unshanked. Shanked buttons are the kind with a little stem on the button back. Unshanked buttons feature sewing holes which go right through them. When using an unshanked button on hand-knit, it's smart to create a thread shank as the button is sewn on. Matching shank height to band thickness prevents puckering and wear from a too-short shank, or drooping from a too-long shank.

Thread shanks
To make a thread shank on an unshanked button, insert a spacer (traditionally a matchstick or a toothpick) between the button and the button band, before sewing down the button. (And here's a trick to hold the spacer in place as you sew.)
Continue sewing the button. When the sewing is complete, remove the spacer. As the last step before knotting off the thread, bring the threaded needle up between the buttonband and the button, then reinforce the shank by winding several times around the sewing threads. Whether a thread shank or a button which comes shanked, match the shank height to the thickness of the buttonhole band: a button shanked high enough for a heavy sweater-coat will droop and wobble buttoned through a thin summer sweater.

Thread shanks
To make a thread shank on an unshanked button, insert a spacer (traditionally a matchstick or a toothpick) between the button and the button band, before sewing down the button. (And here's a trick to hold the spacer in place as you sew.)
Continue sewing the button. When the sewing is complete, remove the spacer. As the last step before knotting off the thread, bring the threaded needle up between the buttonband and the button, then reinforce the shank by winding several times around the sewing threads. Whether a thread shank or a button which comes shanked, match the shank height to the thickness of the buttonhole band: a button shanked high enough for a heavy sweater-coat will droop and wobble buttoned through a thin summer sweater.
Anchor buttons
For a heavy button which wants to droop regardless, consider an anchor button on the inside of the buttonband. An anchor button distributes the weight of a heavy button, and help keep it upright. Conversely, anchor buttons also work well on thin or delicate fabrics: they distribute the weight of the main button, take the strain and prevent ripping at the attachment-point.
Both the main button and the anchor button are sewn at the same time, using the same thread and needle. The main button is shanked-- either by being a shanked button in the first place, or by sewing it on with a thread shank. However, the anchor button is sewn on flat because it is non-functional (it does not go through a buttonhole).
For a heavy button which wants to droop regardless, consider an anchor button on the inside of the buttonband. An anchor button distributes the weight of a heavy button, and help keep it upright. Conversely, anchor buttons also work well on thin or delicate fabrics: they distribute the weight of the main button, take the strain and prevent ripping at the attachment-point.
Both the main button and the anchor button are sewn at the same time, using the same thread and needle. The main button is shanked-- either by being a shanked button in the first place, or by sewing it on with a thread shank. However, the anchor button is sewn on flat because it is non-functional (it does not go through a buttonhole).
Good knitting!--TK
__________________
*(Posts in this series)
.Buttonholes in hand knitting, part 1: lore and tradition plus some nifty tricks
(Related posts)

